1. Field of the Invention
The invention relates to a lamp and more particularly to a light emitting diode (LED) lamp.
2. Description of Related Art
Light emitting diodes (LEDs) are semiconductor devices. Light emitting chips are mainly fabricated using compounds of group III-V elements, for example, gallium phosphide (GaP) or gallium arsenide (GaAs). Moreover, LEDs emit light by converting electric energy into light energy. In details, LEDs apply currents to compound semiconductors so as to release excess energy in the form of light through the binding of electrons and holes. Since the light emitting phenomenon of LEDs does not occur through thermo-luminescence or discharge-luminescence, the lifespan of LEDs can be longer than one hundred thousand hours. LEDs further include advantages such as fast response speed, small volume, energy saving, low pollution, high reliability, suitable for mass production, and so on. Thus, LEDs can be widely applied in various fields, for instance, large display boards, traffic lights, cellular phones, scanner, light sources of fax machines, LED lamps, and the like.
An LED lamp is constituted by a lamp shade, an LED light source in the lamp shade, a power connector connected to the lamp shade, and so on. The power connector is plugged into an external socket to provide the light source required by the LED lamp. The lamp shade and the power connector are generally assembled together through attaching, the lamp shade thereby can not rotate relative to the power connector for adjusting an illumination direction.